Process for the approximate separation of solid and liquid fatty acids



Patented Feb. 27, 1934 I PROCESS FOR APPROXIMATE SEPARA- TION OF SOLID AND LIQUID FATTY ACIDS Ernst Schlenker, Berlin, Germany No Drawing. Application April 4, 1931, Serial lilo. 527,855. In Germany April 11, 1930 9 Claims.

10 termed olein, whilst the residue from the warm,

pressing furnishes the solid acids (stearine) The process is cumbrous, requires expensive apparatus, takes up a great deal of time (several days in many cases), and entails the production of considerable quantities of semi-products (for example the runnings from the warm pressing) which have to be put through the manufacturing.

process-again.

According to the present invention, the apzo proximate separation is effected in the simplest manner by first transforming the neutral fats or their fatty acids. into soaps, and then, by a suitable selection of the kind and quantity of the saponifying agents, ensuring that at least two as different salts of the fatty acids (soaps) are present together. For example, the saponiflcation is effected with lime and caustic sodasolution, the amounts of the two reagents being so apportioned that each of them is/insufllcient in itself so for complete. saponiflcation, but that their joint amount corresponds to the quantity of alkali required for complete saponiflcation at least, as calculated from the saponiilcation value. x The reaction is performed in an aqueous medium and,

' 5 under the specified conditions, produces, s'ide by side, lime soaps which are insoluble in water and water-soluble soda soaps. It is found that if the ratio of lime to soda corresponds to the ratio of solid to liquid fatty acids in the neutral fat, the insoluble precipitate consists almost exclusively of lime salts of the solid fatty acids, whereas the liquid fatty acids remain in solution as soda soaps. If lime be replaced by baryta, and caustic soda by caustic potash, the solid fatty acids will appear as barium salts, the liquid acids as potash salts, and so on. The two phases can be separated by filtration of in any other suitable manner, and, by decomposing the filtrate with acids, nearly pure technical olein .is obtained,

whilst the solid fatty acids are recovered by similarly treating the flltration'residue. Of course,

' the soda and lime soaps can be used, as such, in any convenient manner (without being decom- 66 posed by acidification) for examplqby producing washing soaps through transposing the lime soaps with soda (the Krebitz process), and so on.

Modifications of the process are feasible providedin all cases the essential point of viewis retained of producing a soluble soap and an insoluble soap side by 'side, and the ratio of the saponification agents employed is adapted to the proportions of solid and liquid fatty acids in the originating fats. It has already been stated that the kinds of the saponifying ents can be varied. 05 It is also within the scope of the invention to operate in such a way that, instead of attempting to obtain complete separation of the solidvand liquid fatty acids, the ratio of the saponifying agents is so apportioned that only a predetermined amount [0 of the solid fatty acids passes into the insoluble soaps, and vice versa. The operation may also be conducted so that the neutral fat is first completely transformed into soda soaps, after which a portion of such soaps is transformed into insoluble lime soaps by adding the amount of lime calculated in accordance with the percentage of solid fatty acids in the original fat. Conversely, a lime soap maybe first quantitatively formed and then partially transformed into soda soap by 0 adding soda, this time in the amount approximately corresponding to the percentage of liquid fatty acids.

The fats are preferably saponified in the warm,

and the fatty acids separated in the cold. 35

Example 290 kg. of bone fat (45% oleic acid, 55% stearic acid) are heated to partial saponification with 15 kg. of calcium hydrate (from marble, and of 90 about 90% purity) and a sufiicient amount of water. 29 litres of technical soda lye (about 40% by volume) are then gradually added until complete saponification occurs. The resulting mass is introduced into an excess of cold water and is left a short timefor cooling and the formation of a readily filterable grain. The separation is then eifected by means of filter presses, centrifuges or'other known appliances. The filtrate is acidified with sulphuric acid or some other acid, without any previous re-warming, and the olein collecting at the top is separated from the acid liquid. On similarly decomposing the filtration residue, but in this case with the application of warmth, the stearine is obtained.

I claim:-

1. Process for the separation of the solid and liquid fatty acids contained in, neutral fats or their fatty acids, consisting informing a soluble no and an insoluble soap in water by saponiflcation of the material with two different alkalis one of which includes sodium hydroxide and is able to furnish a water soluble soap and the other of which includes calcium hydroxide and furnishes a water insoluble soap each in an amount insufficient for complete saponification, separating the resulting precipitate from the soluble soap, and re-transforming the soaps separately into fatty acids by acidification.

2. Process for the separation of the solid and liquid fatty acids contained in neutral fats or their fatty acids, consisting in forming a soluble and an insoluble soap in water by saponification of the material with two different alkalis one of which includes sodium hydroxide and is able to furnish a water soluble soap and the other of which includes barium hydroxide and furnishes a water insoluble soap each in an amount insufficient for complete saponification but in a ratio whereby a predetermined portion of the solid fatty acids passes into the insoluble soap, separating the resulting precipitate from the soluble soap, and re-transforming the soaps separately into fatty acids by'acidification.

3. Process for the separation of the solid and liquid fatty acids contained in neutral fats or their fatty acids, consisting in first completely transforming the material into an alkaline earth insoluble soap, converting the liquid fatty acids in the mass. to a soluble soap in water by treating the mass with an amount of alkali compound which includes sodium hydroxide and is able to furnish a water soluble soap substantially equivalent to the liquid fatty acids present, separating the soluble and insoluble soaps, and re-transforming the soaps separately into fatty acids by acidification.

4. Process for the separation of the solid and liquid fatty acids contained in neutral fats or their fatty acids, consisting in first completely transforming the material into a soluble soap, converting the solid fatty acids in the mass to an alkaline earth insoluble soap in water by treating the mass with an amount of metallic compound including calcium able to furnish a water insoluble soap substantially equivalent to the solid fatty acids present, separating the soluble and insoluble soaps, and re-transforming the soaps separately into fatty acids by acidification.

5. Process for the separation of the solid and liquid fatty acids contained in neutral fats or their acids, consisting in forming a soluble and an insoluble soap in water by saponification of the material in a warm state with two different alkalis one of which includes sodium hydroxide and is able to furnish a water soluble soap and the other of which includes calcium hydroxide and furnishes a water insoluble soap each in an amount insufiicient for complete saponification, separating the resulting precipitate from the soluble soap in the cold, and re-transforming the soaps separately into fatty acids by acidification.

6. Process for the separation of the solid and liquid fatty acids contained in neutral fats or their fatty acids, consisting in forming a soluble and an insoluble soap in water by saponification of the material in a warm state with two different alkalis comprising calcium and sodium hydroxides each in an amount lnsufiicient for complete saponification but in a ratio whereby a predetermined portion of the solid fatty acids passes into the insoluble soap, separating the resulting precipitate from the soluble soap in the cold, and re-transforming the soaps separately into fatty acids by acidification.

7. Process for the separation of the solid and liquid fatty acids contained in neutral fats or their fatty acids, consisting in first completely transforming the material into an alkaline earth insoluble soap in a warm state, converting the liquid fatty acids in the mass to a soluble soap in water by treating the mass in the cold with an amount of alkali compound substantially equivalent to the liquid fatty acids present, separating the soluble and insoluble soaps, and re-transforming the soaps separately into fatty acids by acidification.

' 8. Process for the separation of the solid and liquid fatty acids contained in neutral fate or their fatty acids, consisting in first completely transforming the material into a soluble soap in a warm state, converting the solid fatty acids in the mass to an alkaline earth insoluble soap in water by treating the mass in the cold with an amount of metallic compound substantially equivalent to the solid fatty acids present, separating the soluble and insoluble soaps, and retransforming the soaps separately into fatty acids by acidification.

9. The process for the separation of the solid and liquid fatty acids contained in neutral fats, consisting in forming a soluble and an insoluble soap in water by saponification of the material in a warm state with two different alkalis comprising barium and sodium hydroxides each in an amount insuflicient for complete saponification but in a ratio whereby a predetermined portion of the solid fatty acids passes into the insoluble soap, separating the resulting precipitate from the soluble soap in the cold, and re-transfonning the soaps separately into fatty acids by acidification.

ERNST SCHLENKER. 

